1. Field of the Invention
The present invention relates generally to the field of molecular biology, cell therapy, gene therapy, and cancer therapy. More particularly, it concerns methods for treatment of a subject by administration of cells comprising somatostatin receptor such as a signaling deficient somatostatin receptor mutant. The invention also generally pertains to methods for therapy that involves constitutively active somatostatin receptor mutants.
2. Description of Related Art
Therapeutic treatment of many human disease states is limited by the systemic toxicity of the therapeutic agents used. Cancer therapeutic agents in particular exhibit a very low therapeutic index, with rapidly growing normal tissues such as skin and bone marrow typically affected at concentrations of agent that are not much higher than the concentrations used to kill tumor cells. For example, gene therapy and cellular therapies have great promise, but they suffer from a lack of methodology for specifically targeting and localization of a gene therapy and/or a cell expressing a recombinant nucleic acid within an organism. Treatment and diagnosis of cancer would be greatly facilitated by the development of compositions and methods for targeted delivery to cancer cells.
Somatostatin receptors are known to be expressed in a large number of human tumors and represent the basis for in vivo tumor targeting. However, not all tumors express somatostatin receptors. In a pre-clinical tumor model, a recombinant somatostatin receptor type 2 (SSTR2) chimera can serve as a reporter gene of gene expression that can be quantified in vivo and can also serve as a growth inhibitor when targeting cancer. However, this SSTR-mediated signaling, such as growth inhibition, may or may not be desirable in different therapy purposes wherein the SSTR-specific targeting is envisioned.
Therefore, there exists a need of novel methods for targeted therapy, especially cancer therapy.